KR101360083B1 - Method and apparatus for search of digital broadcasting - Google Patents

Abstract

The present invention relates to an apparatus and method for searching digital broadcasting.

An embodiment of the present invention determines whether a pilot signal is within a broadcast channel band based on a center frequency of a search broadcast channel when searching for a broadcast channel, and if the pilot signal is not within a broadcast channel band, the center frequency is set to a preset moving range. While moving, it determines the presence of a pilot signal, and if there is a pilot signal, determines whether it is out of the capture range of the demodulator, and corrects and stores the center frequency of the search broadcast channel.

Broadcast channel, auto search, center frequency

Description

Digital broadcasting search apparatus and method {METHOD AND APPARATUS FOR SEARCH OF DIGITAL BROADCASTING}

1 is a waveform diagram of a conventional digital broadcasting search method

2 is a block diagram of a digital broadcasting search apparatus according to an embodiment of the present invention.

3 is a flowchart illustrating a digital broadcast searching method according to an embodiment of the present invention.

4 is a waveform diagram of a digital broadcasting searching method according to an embodiment of the present invention;

Description of the Related Art [0002]

21; MOPEL integrated circuit 22; Demodulation integrated circuit

23; The control unit

The present invention relates to a digital broadcasting search apparatus and method.

When receiving a digital broadcast, an auto scan method is used to search for a broadcast channel. The auto scan method detects whether a broadcast signal exists while increasing the frequency little by little within a predetermined frequency range, and when the broadcast signal is detected, the frequency. It stores various information including broadcast information and channel information which are transmitted to.

As described above, the automatic search for the broadcast channel through the automatic scan method determines whether the pilot signal is present in the broadcast channel band by the demodulator and determines whether the broadcast channel is searched according to how to set the capture range set by the demodulator to miss the broadcast channel. In order not to set the capture range wider, the channel search time becomes significantly longer.

Accordingly, in the conventional broadcast channel automatic search, as shown in FIG. It is gradually set to ± 286 KHz, "B" = ± 429 KHz, "C" = ± 571 KHz, and the maximum capture range of the demodulator is set to Max = ± 857 KHz and searched.

Therefore, when the broadcast channel is automatically searched, it is determined whether the pilot signal of the search broadcast channel is in the broadcast channel band (6, 7 or 8 MHz), and the broadcast including the pilot signal even when there is a pilot signal in the broadcast channel band. Since the center frequency of the channel is accurately corrected within the capture range of the demodulator to determine how far from the center frequency set for the search, the broadcast channel is searched based on the corrected center frequency.

In addition, the reception range is determined according to the capture range setting of the demodulator. In this case, when the capture range is set to A = ± 286 KHz, broadcast reception is possible only within a maximum of 286KHz from side to side based on the center frequency of the broadcast channel. However, the broadcast channel is used by turning the signal little by little without using the center frequency set correctly by the country, the broadcast method, the surrounding environment.

Therefore, in some regions, broadcasts of up to about 1.5MHz may be lost. When the broadcast signal is about 1.5 MHz on the basis of the center frequency, conventionally, the broadcast channel is searched while continuously expanding the capture range in the demodulator, resulting in a long search time due to the setting of a wide capture range. When the maximum capture range of is ± 1MHz, the signal that is about 1.5MHz misaligned cannot be searched.

Therefore, the conventional broadcast channel search has a problem that the search speed of the broadcast channel is slowed and the search time is long because the search range is gradually increased based on the center frequency.

The present invention shortens the broadcast channel search time.

According to an embodiment of the present invention, an MOPEL integrated circuit converting a high frequency signal into an intermediate frequency of a selected broadcasting channel; A demodulation integrated circuit for demodulating and outputting the intermediate frequency; and when a pilot signal is not within a broadcast channel band based on the center frequency of the search broadcast channel, the center frequency of the search broadcast channel is preset when the broadcast channel is searched. The presence of a pilot signal is determined while moving to a moving range of the center frequency, the pilot signal is in a moving range in which the center frequency of the search broadcast channel is shifted, and the center frequency of the search broadcast channel is captured based on a preset center frequency. And a controller for correcting the center frequency of the search broadcast channel that deviates from the spectral position.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a digital broadcast search apparatus according to an embodiment of the present invention, FIG. 3 is a flowchart of a digital broadcast search method according to an embodiment of the present invention, and FIG. 4 is an embodiment of the present invention. Is a waveform diagram of a digital broadcasting search method according to the present invention.

The MLP integrated circuit 21 converts the input high frequency signal into an intermediate frequency corresponding to the selected broadcast channel. The MLP integrated circuit 21 includes an oscillator (0SC), a phase locked loop (PLL), Mixer (MIXER) is included.

The demodulation integrated circuit 22 demodulates the intermediate frequency output from the MOPEL integrated circuit 21 into the original broadcast channel signal, and the center frequency for searching for the broadcast channel through an I2C line. The oscillation frequency of the oscillator 0SC of the MOPEL integrated circuit 21 is varied and moved.

The controller 23 sets the moving range and the capture range of the center frequency for the broadcast channel search in the demodulation integrated circuit 22.

When the demodulation integrated circuit 22 searches for a broadcast channel, the controller 23 determines whether the pilot signal is in a band based on the center frequency of the search broadcast channel. If the pilot signal does not exist, the controller 23 determines whether a fraudulent pilot signal is present while moving the center frequency of the discovery broadcast channel by a predetermined center frequency. If the pilot signal is within a movement range of a preset center frequency or within a broadcast channel band based on the center frequency of the search broadcast channel, the controller 23 determines that the center frequency of the search broadcast channel is based on a preset center frequency. To determine if it is outside the capture range. If not within the capture range, the controller 23 stores the center frequency of the discovery broadcast channel in the memory. On the other hand, if there is a deviation, the controller 23 corrects the intermediate frequency of the deviation search broadcast channel and stores it in a memory.

According to the embodiment of the present invention, the demodulation integrated circuit 22 searches for a broadcast channel by converting a high frequency signal received when searching for a broadcast channel into an intermediate frequency through the MOPEL integrated circuit 21, wherein the pilot signal is broadcast. It is searched whether it is in a channel band (step 31).

At this time, the control unit 23 in the demodulation integrated circuit 22 as shown in Figure 4, the center frequency of the search broadcast channel 850MHz, the capture range of the center frequency ± 429KHz, the movement range of the center frequency (N) ± 840KHz Suppose you set it to. The controller 23 determines whether a pilot signal is present in the channel band based on the intermediate frequency of the discovery broadcast channel (step 32).

Therefore, if the pilot signal is within the broadcast channel band, the controller 23 is out of the capture range (± 429 KHz) based on the center frequency (850 MHz) of the search broadcast channel preset in the demodulation integrated circuit 22. It is judged whether or not there is (step 33).

In this case, the demodulation integrated circuit 22 may be correctly received without departing from the capture range (± 429 KHz) based on the center frequency (850 MHz) of the search broadcast channel or out of the center frequency (850 MHz) of the search broadcast channel. If the deviation is compensated for within the capture range (± 429KHz), the controller 23 determines that the broadcast channel does not have deviation. Accordingly, the controller 23 stores the intermediate frequency of the discovery broadcast channel in a memory (step 34). Subsequently, the controller 23 searches for a broadcast channel while determining whether there is a next broadcast channel (step 35).

On the other hand, if there is the pilot signal, but the center frequency (850MHz) of the search broadcast channel is out of the capture range (± 429KHz) of the demodulation integrated circuit 22, the control unit 23 is the demodulation integrated circuit ( In step 36, the center frequency (850 MHz) of the search broadcast channel that deviates from the capture range (± 429 KHz) of the preset center frequency is corrected.

The controller 23 stores the corrected center frequency of the search broadcast channel in a memory (step 34), and then searches for a broadcast channel while determining whether there is a next broadcast channel (step 35).

On the other hand, if the pilot signal is not in the broadcast channel band based on the center frequency of the search broadcast channel, the controller 23 transmits the MPIEL integrated circuit (I2C) line through the I2C line of the demodulation integrated circuit 22. As shown in FIG. 4 by varying the oscillator (OSC) of 21), the center frequency (850 MHz) of the search broadcast channel is shifted by a predetermined center frequency moving range (N) ± 840 KHz, that is, the center frequency 850 MHz-840 KHz. = 849,160KHz and then the center frequency 850MHz + 840KHz = 850,840KHz.

At this time, the presence or absence of a pilot signal is determined based on the center frequency moving range (N-1) based on the capture range (± 429KHz), that is, the range of 849,160KHz ± 429KHz, and then captured based on the center frequency moving range (N + 1). A range (± 429KHz), that is, a range of 850,840KHz ± 429KHz, is determined, but the widening range of the capture range ± 9KHz is determined to prevent the pilot signal from being missed at the boundary of the intermediate frequency moving range.

If it is not determined whether a pilot signal exists in the center frequency moving range N ± 1, the controller 23 moves by the predetermined moving range N ± 2 of the center frequency, that is, the center frequency 850MHz-1680KHz = 848.320KHz. And then the center frequency 850MHz + 1680KHz = 851.680KHz to determine the gap destination range ± 429KHz based on the center frequency moving range N ± 2, respectively (step 37).

At this time, if there is the pilot signal in any one of the center frequency moving range N ± 1 or N ± 2, the controller 23 controls the center frequency N of the broadcast channel moved to the demodulation integrated circuit 22. On the basis of ± 1, N ± 2, it is determined whether the deviation is within the preset capture range (± 429 KHz) (step 33).

Subsequently, the center frequency of the searched broadcast channel is correctly received or shifted without departing from the center frequency (N ± 1) or (N ± 2) and the capture range (± 429KHz) of the shifted broadcast channel. When the deviation is based on the frequency (N ± 1) or (N ± 2) but compensated within the capture range (± 429 KHz) in the demodulation integrated circuit 22, the control unit 23 determines that the broadcast channel does not escape. By determining, the center frequency of the search broadcast channel is stored in the memory of the controller 23 (step 34), and the broadcast channel is searched while determining whether there is a next broadcast channel (step 35).

However, although the pilot signal is present, the center frequency of the search broadcast channel is out of the shifted center channel frequency (N ± 1) or (N ± 2) within the capture range (± 429 KHz) of the demodulation integrated circuit 22. If so, the control unit 23 transmits the center frequency of the search broadcasting channel out of the moving range N ± 1 or N ± 2 of the center frequency preset to the demodulation integrated circuit 22 and the capture range ± 429KHz. (Step 36), the center frequency of the corrected search broadcast channel is stored in the memory (step 34), and the broadcast channel is searched while determining whether there is a next broadcast channel (step 35).

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

An embodiment of the present invention determines whether a pilot signal is within a broadcast channel band based on a center frequency of a search broadcast channel when searching for a broadcast channel, and if the pilot signal is not within a signal band, shifting a predetermined moving range of the center frequency. While determining the presence or absence of a pilot signal, and if there is a pilot signal, it is possible to shorten the search time of the broadcast channel by correcting and storing the search broadcast channel center frequency while determining the deviation of the center frequency by the capture range of the demodulator.

Claims (6)

An MOPEL integrated circuit converting a high frequency signal into an intermediate frequency of a selected broadcast channel; A demodulation integrated circuit for demodulating and outputting the intermediate frequency; And when the pilot signal is not in the broadcast channel band based on the center frequency of the search broadcast channel when searching for a broadcast channel in the demodulation integrated circuit, moving the center frequency of the search broadcast channel to a moving range of a preset center frequency and having a pilot signal. If the pilot signal is in the moving range of moving the center frequency of the discovery broadcast channel, and the center frequency of the discovery broadcast channel is out of the capture range based on a preset center frequency, the center frequency of the discovery broadcast channel Digital broadcasting search apparatus comprising a control unit for correcting. 2. The center frequency of the discovery broadcast channel according to claim 1, wherein the center frequency of the discovery broadcast channel is set within a broadcast channel band and the center frequency of the discovery broadcast channel does not exceed a capture range of a preset center frequency. Digital broadcasting search device to store in the memory. 3. The center frequency of the discovery broadcast channel according to claim 2, wherein the center frequency of the discovery broadcast channel is located within a broadcast channel band and the center frequency of the discovery broadcast channel is out of a capture range of a preset center frequency. Digital broadcast navigation device to calibrate and store. The center of the search broadcast channel according to claim 1, wherein the pilot signal is in a moving range in which the center frequency of the search broadcast channel is shifted, and the center frequency of the search broadcast channel does not deviate from a capture range of a preset center frequency. Digital broadcast search device for storing frequencies in memory. The digital broadcasting search apparatus of claim 1, wherein the capture range of the center frequency is set to a wider range than the movement range of the center frequency. Determining whether the pilot signal is within a broadcast channel band based on the center frequency of the search broadcast channel; If the pilot signal is within a broadcast channel band, determining whether the center frequency of the discovery broadcast channel is out of a preset capture range based on the center frequency of the broadcast channel; Correcting and storing the center frequency of the discovery broadcast channel in the preset capture range when the center frequency of the discovery broadcast channel is out of the preset capture range; If a pilot signal is not in a broadcast channel band, determining whether a pilot signal is present while moving a center frequency of a discovery broadcast channel to a moving range of a predetermined center frequency; Determining whether a center frequency of the moved broadcast channel is out of a capture range when there is a pilot signal in a movement range of a preset center frequency; And calibrating and storing the center frequency of the search broadcast channel if the center frequency of the moved broadcast channel is outside the capture range.

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